1. Field of the Invention:
The present invention relates to a multi-pole connector having a planar filter with a number of condensers corresponding to a number of signal lines to be connected, a condenser is disposed in conjunction with each terminal pin/socket of the multi-pole connector and is formed from a first coating to be connected through contact surfaces to an appropriate signal line, a second coating to be connected to ground through at least one edge strip and a dielectric layer interposed between the two coatings.
Multi-pole connectors which are employed either in transmitting digital or analog test or measuring signals from a multiplicity of testing devices or which are used in high-speed data transmission, require a filtering device in order to filter out interfering signals. The filtering of absorbed interference signals is accomplished, generally speaking, by using condensers that are disposed based on one per signal-carrying line. For that purpose, the condensers are advantageously grouped together in planar filters and used inside the multi-pole connectors.
In such a configuration, the planar filters are traversed by the signal lines and at least one condenser is provided for each of the signal-carrying lines. The condensers are disposed on one carrier which is, generally speaking, a ceramic, and in particular an aluminum-oxide carrier or the like. Should the individual signal leads be formed of pins that are pressed into plastic members or sections (as in "fit-in" connections), such pins cannot be soldered to the coating of the signal-electrodes that extend into the sockets. That type of multi-pole connector is disclosed, for example, in U.S. Pat. No. 3,447,104 and Published European Application No. 0 398 807. Employed inside those connectors are planar filters which are, as a rule, applied on top of an aluminum oxide substrate by using a screen printing procedure, in which the electrodes, (which are separated from each other by a non-conducting layer) are imprinted onto the layer first as a continuous ground electrode and second as discrete electrodes. The number of electrodes, which are insulated from each other, corresponds to the number of pins or, alternatively, sockets in the multi-pole connector. By virtue of their construction, such planar filters possess very low self-inductance, which causes their resonance to shift toward high frequencies, thus favoring application of such technology in high-speed signal transfer.
In such configurations, the planar filters are provided with openings through which the connecting pins, or sockets, are introduced, in which case the coating of the corresponding condenser is advantageously introduced into the opening where the electrical connection to the connecting pin or socket is achieved through soldering. However, in a few cases geometry prevents the planar filters from being disposed at right angles to either connecting pins or sockets.